The invention relates to a miniaturized dynamoelectric machine structure.
Such machine structures are known for example in the form of linear motors which, to produce a limited stroke movement, include a hollow permanent magnet which is in the form of a straight circular cylinder. An electrical winding passes into the field of the permanent magnet which is firstly directed inwardly and is then deflected by means of a magnetic yoke arrangement parallel to the longitudinal axis towards an end of the permanent magnet. Depending on the direction of the current flowing through the electrical winding, the electrical winding moves closer towards or away from the end of the arrangement, through which the main portion of the magnetic flux passes. With such an arrangement, a uniform force effect can be achieved only as long as the winding is enclosed by the permanent magnet over practically the entire axial length of the winding. Therefore the permanent magnet must be longer in the axial direction than the winding by the desired stroke movement.
That means that the known electric motors are not of the optimum nature in regard to the requirement of producing a maximum force or a maximum moment, while being of minimum structural size.